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1.
Transplant Proc ; 48(4): 1083-6, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27320563

RESUMO

BACKGROUND: In this study, we demonstrated our new device for open donor liver surgery with left-sided heptectomy by use of the real-time moving windows (RTMW) method with 8-cm transverse skin incision for living donors from the viewpoints of cosmetic, economic, and safety procedures. METHODS: After the upper abdominal 8-cm transverse skin incision was made, the subcutaneous area was exfoliated and the reverse T-shaped-abdominal incision was made, as in open surgery. After that, the 2 Kent hooks for the upper region and the 2 surgical arms for the lower region were placed. The operative fields of hepatic vein, hepatic hilus, and common hepatic artery were explored, respectively, by use of the RTMW method with the use of the 4 surgical hooks. Hepatic parenchymal dissection was carried out with the use of CUSA and laparosonic coagulating shears. Manipulations of 3 hepatic vessels and the hepatic duct were done by the usual procedure of open surgery. RESULTS: This operative procedure could be performed without laparoscopic techniques. The operative time was 7 hours, without blood transfusion. The operative course was uneventful, and the patient was discharged on postoperative day 11. CONCLUSIONS: Our RTMW method for donor left-sided hepatectomy is considered to be a useful operative procedure from the viewpoints of donor safety, cosmetic advantage, and cost performance.


Assuntos
Dissecação/instrumentação , Hepatectomia/métodos , Transplante de Fígado , Doadores Vivos , Coleta de Tecidos e Órgãos/métodos , Idoso de 80 Anos ou mais , Neoplasias dos Ductos Biliares/cirurgia , Colangiocarcinoma/cirurgia , Feminino , Humanos , Duração da Cirurgia , Sítio Doador de Transplante
2.
AJNR Am J Neuroradiol ; 37(10): 1851-1859, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27339950

RESUMO

BACKGROUND AND PURPOSE: The stiffness of intracranial tumors affects the outcome of tumor removal. We evaluated the stiffness of 4 common intracranial tumors by using MR elastography and tested whether MR elastography had the potential to discriminate firm tumors preoperatively. MATERIALS AND METHODS: Thirty-four patients with meningiomas, pituitary adenomas, vestibular schwannomas, and gliomas scheduled for resection were recruited for MR elastography. On the elastogram, the mean and the maximum shear stiffnesses were measured by placing an ROI on the tumor. Blinded to the MR elastography findings, surgeons conducted qualitative intraoperative assessment of tumor consistency by using a 5-point scale. Histopathologic diagnosis was confirmed by using the resected specimens. The mean and maximum shear stiffnesses were compared with histopathologic subtypes, and the intraoperative tumor consistency was graded by the surgeons. RESULTS: The mean and maximum shear stiffnesses were the following: 1.9 ± 0.8 kPa and 3.4 ± 1.5 kPa for meningiomas, 1.2 ± 0.3 kPa and 1.8 ± 0.5 kPa for pituitary adenomas, 2.0 ± 0.4 kPa and 2.7 ± 0.8 kPa for vestibular schwannomas, and 1.5 ± 0.2 kPa and 2.7 ± 0.8 kPa for gliomas. The mean and maximum shear stiffnesses for meningiomas were higher than those of pituitary adenomas (P < .05). The mean and maximum shear stiffnesses were significantly correlated with the surgeon's qualitative assessment of tumor consistency (P < .05). The maximum shear stiffness for 5 firm tumors was higher than that of nonfirm tumors (P < .05). CONCLUSIONS: MR elastography could evaluate intracranial tumors on the basis of their physical property of shear stiffness. MR elastography may be useful in discriminating firm tumors preoperatively.

3.
Eur J Gynaecol Oncol ; 37(6): 864-866, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-29943938

RESUMO

An atypical polypoid adenomyoma (APAM) is a benign mixed epithelial and mesenchymal uterine tumor. Patients typically present with hypermenorrhea or abnormal uterine bleeding, and the tumor is most commonly found in nulliparous or infertile women of reproductive age. The natural pathological course of an APAM remains unclear because of the rarity of the disease. The coexistence or sequential development of low-grade malignant endometrial tumors has been reported; however, reports of a mixed carcinoma arising from an APAM have not been published yet. In this report, the authors describe the case of a woman with a mixed carcinoma of the uterus arising from an APAM. This case extends our knowledge of the natural pathological course of an APAM and its etiological relationship with a mixed carcinoma of the uterus, which may contribute to the development of management strategies for an APAM.


Assuntos
Adenomioma/patologia , Carcinoma/patologia , Neoplasias Uterinas/patologia , Adulto , Feminino , Humanos
4.
Eur J Vasc Endovasc Surg ; 46(3): 321-8, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23880423

RESUMO

OBJECTIVES: Many pancreaticoduodenal artery (PDA) aneurysms are associated with celiac artery (CA) stenosis. The pathogenesis of PDA aneurysm may be associated with hemodynamic changes due to CA stenosis/occlusion. The aim of this study was to assess the hemodynamic changes of celiaco-mesenteric anastomosis in patients with PDA aneurysms concomitant with CA occlusion using four-dimensional flow-sensitive magnetic resonance imaging (4D-Flow). METHODS: 4D-Flow was performed preoperatively on five patients. Seven age- and sex-matched individuals were used as controls. Hemodynamic parameters such as flow volume and maximum flow velocity in PDAs, gastroduodenal arteries, common hepatic arteries, and superior mesenteric arteries were compared between both groups. Wall shear stress (WSS) and oscillatory shear index (OSI) were mapped in both groups. RESULTS: In the patient group, 4D-Flow identified retrograde flow of both gastroduodenal arteries and common hepatic arteries. Heterogeneous distribution patterns of both WSS and OSI were identified across the entire PDA in the patient group. OSI mapping showed multiple regions with extremely high OSI values (OSI > 0.3) in all patients. All PDA aneurysms, which were surgically resected, were atherosclerotic. CONCLUSIONS: 4D-Flow identified hemodynamic changes in celiaco-mesenteric arteries in patients with PDA aneurysms with concomitant CA occlusion. These hemodynamic changes may be associated with PDA aneurysm formation.


Assuntos
Aneurisma/fisiopatologia , Aneurisma/cirurgia , Aterosclerose/fisiopatologia , Artéria Celíaca , Duodeno/irrigação sanguínea , Hemodinâmica/fisiologia , Artéria Hepática , Angiografia por Ressonância Magnética/métodos , Artéria Mesentérica Superior , Pâncreas/irrigação sanguínea , Anastomose Cirúrgica , Estudos de Casos e Controles , Meios de Contraste , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Estatísticas não Paramétricas , Estresse Mecânico
5.
AJNR Am J Neuroradiol ; 34(11): 2139-43, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23721898

RESUMO

BACKGROUND AND PURPOSE: Angiogenesis is very important in clinical features of pituitary adenomas. We investigated the relationship between the blood flow of nonfunctioning pituitary macroadenomas measured by arterial spin-labeled perfusion imaging and the microvessel attenuation of the tissue. MATERIALS AND METHODS: Conventional MR imaging with contrast-enhanced T1WI and arterial spin-labeled perfusion imaging were performed before surgery in 11 consecutive patients with nonfunctioning pituitary macroadenomas. ROIs were drawn on the tumors, and the degrees of enhancement were calculated by dividing the signal intensity on the contrast-enhanced T1WI by that on the nonenhanced TIWI. As an index of tumor perfusion, a quantitative analysis was performed by using normalized tumor blood flow values calculated by dividing the mean value of the tumor region of interest by the mean region of interest values in the 2 cerebellar hemispheres. The relative microvessel attenuation was determined as the total microvessel wall area divided by the entire tissue area on CD-31-stained specimens. The degree of enhancement and the normalized tumor blood flow values were compared with relative microvessel attenuation. Additionally, intra- and postoperative tumor hemorrhages were visually graded. RESULTS: The degree of enhancement was not correlated with relative microvessel attenuation. Statistically significant correlations were observed between normalized tumor blood flow values and relative microvessel attenuation (P < .05). At surgery, 3 cases were visually determined to be hypervascular tumors, and 1 of these cases had symptomatic postoperative hemorrhage. A statistically significant difference in normalized tumor blood flow values was observed visually between the intraoperative hypovascular and hypervascular groups (P < .05). CONCLUSIONS: Arterial spin-labeled perfusion imaging reflects the vascular density of nonfunctioning pituitary macroadenomas, which may be useful in the preoperative prediction of intra- and postoperative tumor hemorrhage.


Assuntos
Adenoma/complicações , Adenoma/patologia , Angiografia por Ressonância Magnética/métodos , Neovascularização Patológica/complicações , Neovascularização Patológica/patologia , Neoplasias Hipofisárias/complicações , Neoplasias Hipofisárias/patologia , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Marcadores de Spin
6.
Int J Numer Method Biomed Eng ; 29(10): 1089-103, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23733738

RESUMO

In the patient-specific vascular CFD, determination of the inlet and outlet boundary conditions (BCs) is an important issue for a valid diagnosis. The 3D cine phase-contrast MRI (4D Flow) velocimetry is promising for this issue; yet, its measured velocities contain relatively large error and are not admissible as the BCs without any correction. This paper proposes a novel correction method for determining the BCs accurately using the 4D Flow velocimetry. First, we reveal that the error of the velocity measured by the 4D Flow at each measurement voxel is large but is distributed symmetrically. Secondly, our method pays attention to the incompressibility of the blood and the fact that the volume flow rate (VFR) in each vessel is constant on any cross sections. We reveal that the average of the cross-sectional VFRs integrated from many measurement voxel in each vessel is accurate despite the large error. Finally, we propose the novel correction method, which applies a smoothing to the measured velocities on each inlet or outlet boundary with a low-pass filter and then corrects them with the VFR. The results of the several phantom studies are presented to validate the accuracy of our method. A demonstrative analysis for an actual aneurysm is also presented to show the feasibility and effectiveness of our method.


Assuntos
Hemodinâmica/fisiologia , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Humanos , Modelos Teóricos , Reologia
7.
Br J Radiol ; 80(959): 878-83, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17989332

RESUMO

Pseudoneoplastic glandular lesions are benign lesions that are often histologically and radiographically confused with adenoma malignum, which is a rare variant of mucinous adenocarcinoma of the uterine cervix. 15 cases of pseudoneoplastic glandular lesions, characterized by multilocular cystic masses in the uterine cervix, were investigated; these lesions included endocervical glandular hyperplasia, deep nabothian cysts and tunnel cluster. All lesions were proven by conization or hysterectomy. The MR findings correlated closely to the histopathological specimens. As a result, MR findings of pseudoneoplastic glandular lesions were almost identical to those of adenoma malignum; hence, it was almost impossible to differentiate between the two pathologies. Radiologists should be aware that these two conditions are quite similar in morphology.


Assuntos
Adenocarcinoma Mucinoso/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Estudos Retrospectivos , Doenças do Colo do Útero/diagnóstico
8.
Acta Radiol ; 48(6): 704-6, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17611882

RESUMO

We report the magnetic resonance (MR) findings of clear-cell adenocarcinofibroma of the ovary. A huge multilocular cystic tumor with solid components was seen in the lower abdominal and pelvic cavity. Thickened cyst wall had low intensity on T2-weighted images, which suggested abundant fibrous tissue. Its mural nodules were strongly enhanced on contrast enhancement, which reflected malignant epithelial growth. Adenocarcinofibroma of the ovary is a rare tumor, but MR findings may be helpful to reach the correct diagnosis.


Assuntos
Adenocarcinoma de Células Claras/diagnóstico , Fibroma/diagnóstico , Imageamento por Ressonância Magnética/métodos , Neoplasias Ovarianas/diagnóstico , Ovário/patologia , Abdome/diagnóstico por imagem , Abdome/patologia , Dor Abdominal/etiologia , Adenocarcinoma de Células Claras/cirurgia , Idoso , Meios de Contraste/administração & dosagem , Diagnóstico Diferencial , Feminino , Fibroma/cirurgia , Seguimentos , Humanos , Aumento da Imagem/métodos , Neoplasias Ovarianas/cirurgia , Ovário/cirurgia , Pelve/diagnóstico por imagem , Pelve/patologia , Doenças Raras , Ultrassonografia
9.
Clin Radiol ; 62(7): 688-93, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17556039

RESUMO

AIM: To elucidate the mechanism of occurrence of splanchnic artery aneurysm associated with coeliac artery stenosis due to compression by the median arcuate ligament, and also to discuss the management for this relatively rare condition. MATERIALS AND METHODS: Five consecutive cases of splanchnic artery aneurysm associated with coeliac axis stenosis due to compression by the median arcuate ligament, including four cases of pancreaticoduodenal artery aneurysm and one case of epiploic artery aneurysm, were investigated. These cases were collected over a 5-year period in our local and affiliated hospitals. Among these five cases, three were discovered because of rupture of the aneurysm, and two were found incidentally in annual medical check-ups. RESULTS: In all cases, conspicuously developed collateral arteries, which were of the dilated pancreaticoduodenal arcade and its branches, were conspicuously found on digital subtraction angiography of the superior mesenteric artery. The findings suggested that haemodynamic changes in the splanchnic arterial networks (an increase in blood flow mainly through the pancreaticoduodenal arcade), were the possible cause of the corresponding aneurysms. CONCLUSION: Compression by the median arcuate ligament might be a frequent cause of splanchnic aneurysm, which, on rupture of the aneurysm, could be life-threatening.


Assuntos
Aneurisma/etiologia , Arteriopatias Oclusivas/etiologia , Artéria Celíaca/diagnóstico por imagem , Ligamentos , Doenças Musculares/complicações , Artéria Esplênica/diagnóstico por imagem , Idoso , Aneurisma/diagnóstico por imagem , Aneurisma Roto/diagnóstico por imagem , Aneurisma Roto/etiologia , Aneurisma Roto/terapia , Arteriopatias Oclusivas/diagnóstico por imagem , Constrição Patológica/diagnóstico por imagem , Constrição Patológica/etiologia , Diafragma , Embolização Terapêutica/métodos , Feminino , Humanos , Achados Incidentais , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
14.
Heart ; 90(2): 175-80, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14729790

RESUMO

OBJECTIVE: To assess the long axis function of both ventricles during the early neonatal period by using pulsed wave Doppler tissue (PWDT) echocardiography. DESIGN: PWDT echocardiography was recorded from the lateral sites of the mitral and tricuspid annuluses and the tip of interventricular septum in 130 neonates within 24 hours after birth (day 0 group), in 135 neonates 1-7 days after birth (day 1-7 group), and in 131 healthy children (children group). RESULTS: Peak systolic motion velocity (Sw) of the three ventricular walls positively correlated with the number of days after birth (p < 0.005). Compared with the children group, in neonates Sw in the right ventricle and peak early diastolic motion velocity (Ew) and peak atrial systolic motion velocity in the interventricular septum were lower than in the remaining two walls (p < 0.0005, p < 0.0001, and p< 0.0001, respectively). Although peak mitral and tricuspid flow velocities during early diastole (E) correlated with the number of hours after birth in the day 0 group, there was no significant change in the Ew of either ventricle. The E:Ew ratio of both ventricles was significantly higher in both neonate groups than in the children group (p < 0.001). The E:Ew ratio of the left ventricle was higher in the day 0 group than in the day 1-7 group (p < 0.005). CONCLUSIONS: The two ventricles differ in their normal PWDT echocardiographic values and in the parameter change after birth during the early neonatal period, which may reflect differences in ventricular adaptation after birth.


Assuntos
Função Ventricular Esquerda/fisiologia , Função Ventricular Direita/fisiologia , Ecocardiografia Doppler de Pulso , Idade Gestacional , Humanos , Recém-Nascido , Variações Dependentes do Observador , Sístole/fisiologia
15.
Biochem Pharmacol ; 62(7): 821-8, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11543718

RESUMO

The biochemical properties and specificity of n-3 and n-6 polyunsaturated fatty acids (PUFAs) are not well known. Because PUFAs induce apoptosis of different cells, we studied the effect of various PUFAs, such as arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosapentaenoic acid (DPA), on the fate of cultured human promyelocytic leukemia cells (HL-60) to elucidate the mechanism of apoptosis and the difference in action between n-3 and n-6 PUFAs. Fairly low concentrations of PUFAs inhibited the growth of HL-60 cells and induced their apoptosis by a mechanism that is sensitive to DMSO, an antioxidant, and z-Val-Ala-Asp(OMe)-fluoromethylketone (z-VAD-fmk), a pan-caspase inhibitor. PUFAs stimulated the generation of reactive oxygen species (ROS) and activated various types of caspase-like proteases, such as caspase-3, -6, -8, and -9, but not caspase-1. In addition, PUFAs triggered the reaction leading to the cleavage of Bid, a death agonist member of the Bcl-2 family, and also released cytochrome c from mitochondria into the cytosol. PUFAs also decreased the mitochondrial membrane potential of intact HL-60 cells. All of these actions of n-3 PUFAs were stronger than those of AA, an n-6 PUFA, although the mechanism is not known. PUFAs stimulate swelling and membrane depolarization of isolated mitochondria in a cyclosporin A-sensitive manner. The results indicated that PUFA-induced apoptosis of HL-60 cells may be caused, in part, by direct action on the cells and by activation of the caspase cascade through cytochrome c release coupled with mitochondrial membrane depolarization.


Assuntos
Apoptose , Ácidos Graxos Insaturados/farmacologia , Células HL-60/efeitos dos fármacos , Triglicerídeos/farmacologia , Clorometilcetonas de Aminoácidos/farmacologia , Caspases/metabolismo , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Inibidores de Cisteína Proteinase/farmacologia , Grupo dos Citocromos c/metabolismo , DNA/efeitos dos fármacos , DNA/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Ácidos Graxos Ômega-3 , Ácidos Graxos Ômega-6 , Células HL-60/patologia , Humanos , Potenciais da Membrana/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia
16.
Eur J Radiol ; 39(3): 139-46, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11566239

RESUMO

Dynamic magnetic resonance (MR) imaging for pituitary adenomas is usually performed in a coronal direction; however, small lesions between slices, or lesions located at the anterior or posterior aspect of the pituitary gland might be overlooked on MR images in only the coronal direction. The purpose of our study was to evaluate whether consecutive dynamic MR images in the coronal and sagittal planes improve detection of pituitary adenomas. Eighteen patients with pituitary microadenomas and nine with healthy pituitary glands were included in this study. MR images were performed with 1.5 T superconductive units and commercially-available head coils. After a 5 ml gadolinium contrast injection, eight serial dynamic sagittal images were obtained. Within 3 or 6 min, this was followed by a 10-15 ml gadolinium injection and acquisition of eight serial dynamic coronal images. Dynamic MR images and conventional noncontrast- and contrast-enhanced sagittal and coronal T1-weighted images were evaluated independently in a blind fashion by two neuroradiologists regarding the depiction of pituitary microadenomas. The sensitivities of dynamic enhanced MR imaging in the detection of microadenomas were 61.1% in sagittal direction, 72.2% in coronal direction respectively, and were superior to those of conventional noncontrast- and contrast-enhanced T1-weighted imaging (22.2-50%). The sensitivity of a combination of sagittal and coronal dynamic enhanced MR imaging for the detection of microadenomas was 88.9% and was superior to those of conventional noncontrast- and contrast-enhanced T1-weighted imaging combining sagittal and coronal directions (61.1%, 61.1%) (P<0.05, P<0.05, respectively). The specificity and accuracy of dynamic enhanced MR imaging with combination of sagittal and coronal images was 88.9% respectively. Dynamic gadolinium-enhanced MR imaging, especially using both sagittal and coronal planes, was concluded to be useful for the detection of pituitary microadenomas.


Assuntos
Adenoma/diagnóstico , Imageamento por Ressonância Magnética , Neoplasias Hipofisárias/diagnóstico , Adulto , Meios de Contraste , Feminino , Gadolínio DTPA , Humanos , Masculino , Sensibilidade e Especificidade , Fatores de Tempo
17.
Neuroreport ; 12(10): 2227-30, 2001 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-11447339

RESUMO

Cortical areas used in the copying of Japanese ideographic characters and syllabic characters were studied using functional magnetic resonance imaging in healthy volunteers. Complexity of characters was controlled to illustrate differences resulting from character to sound conversion differences between the ideographic and syllabic characters. Statistical comparisons indicated extensive activation in the fusiform gyrus, posterior portions around the intraparietal sulcus and in the conjunction area of BA 6, 9 and 44 (which is assumed to be Exner's area) during the copying of ideographic characters. These findings suggested that indirectness between ideographic characters and their pronunciation demands extra processing such as semantic mediation and intensive grapheme processing in comparison with syllabic characters.


Assuntos
Encéfalo/fisiologia , Escrita Manual , Leitura , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino
18.
Br J Cancer ; 84(12): 1681-5, 2001 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-11401324

RESUMO

The purpose of the study is to evaluate the tumour enhancing characteristics and biodistribution of a newly developed metalloporphyrin derivative, HOP-9P (13, 17-bis (1-carboxypropionyl) carbamoylethyl-3, 8-bis (1-phenylpropyloxyethyl)-2,7,12,18-tetra- methyl-porphynato manganese (III)). Seven mice bearing SCC VII tumours were imaged using T1-weighted conventional spin echo magnetic resonance images before and 5 min, 2 h and 24 h after intravenous injection of 0.1 mmol/kg of HOP-9P. For the acquired images, signal intensities of the tumour, muscle and oil-phantom were measured. Then, tumor/oil and tumor/muscle signal intensity ratios were calculated. Nineteen mice were sacrificed before or after the administration of HOP-9P (at 5 min, 2 h and 24 h), and the biodistribution of manganese in the tumour, muscle, liver, blood and kidneys was measured using optical emission spectrometers and was expressed as micrograms of manganese per gram of tissue. The tumour/muscle signal intensity ratio at 24 h (3.18 +/- 0.34) was significantly higher than precontrast ratio (1.77 +/- 0.20) (P < 0.05). The biodistribution assessment of manganese demonstrated that HOP-9P gradually and consistently accumulated in the tumour to reach the highest concentration at 24 h (3.49 +/- 1.22 micro gMn/g). It is concluded that HOP-9P is a potential tumour-specific MR contrast agent.


Assuntos
Carcinoma de Células Escamosas/patologia , Meios de Contraste/farmacocinética , Imageamento por Ressonância Magnética/métodos , Metaloporfirinas/farmacocinética , Neoplasias Cutâneas/patologia , Animais , Meios de Contraste/administração & dosagem , Injeções Intravenosas , Masculino , Manganês , Metaloporfirinas/administração & dosagem , Camundongos , Neoplasias Experimentais , Distribuição Tecidual
19.
J Comput Assist Tomogr ; 25(3): 436-45, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11351196

RESUMO

To predict the potential and the limitations of functional MRI (fMRI) with a very high field magnet, the detectability and reproducibility of activation were evaluated by comparing the activation induced by a sequential finger movement task at 1.5 T with that at 3 T. The detectability of the premotor area, supplementary motor area (SMA), and ipsilateral sensorimotor area (SM1) showed significant improvement at 3 T. On the other hand, the detectability of contralateral SM1 was not significantly different between 1.5 and 3 T. The degree of activation was proportional to task demand in the ipsilateral SM1 and SMA, whereas that in the contralateral SM1 and SMA was not. FMRI with a 3 T magnet has greater potential for detection of neuronal activation as a functional network. These observations indicated that task demand and static magnetic field strength should be considered in interpretation of fMRI data for clinical usage.


Assuntos
Dedos/fisiologia , Imageamento por Ressonância Magnética/métodos , Córtex Motor/fisiologia , Movimento/fisiologia , Adulto , Análise de Variância , Circulação Cerebrovascular/fisiologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Córtex Motor/irrigação sanguínea , Reprodutibilidade dos Testes , Estatísticas não Paramétricas
20.
AJR Am J Roentgenol ; 176(5): 1213-9, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11312184

RESUMO

OBJECTIVE: The purpose of this study was to assess the image quality of gadolinium-enhanced time-resolved three-dimensional (3D) MR angiography and to evaluate its accuracy in revealing renal artery stenosis. SUBJECTS AND METHODS: Thirty-nine patients underwent MR angiography using an ultrafast 3D Fourier transform spoiled gradient-recalled acquisition in the steady state (TR/TE range, 2.6/0.7--0.8). Five seconds after administration of 15--20 mL gadodiamide hydrate, four or five consecutive data sets with imaging times of 7.0--7.6 sec were acquired during a single breath-hold. A timing examination was not performed. Image quality was assessed using quantitative analysis (signal-to-noise, contrast-to-noise, and venous-to-arterial enhancement ratios) and qualitative analysis (presence of venous overlap, presence of artifacts, and degree of renal arterial enhancement). MR angiography depiction of the renal artery stenosis was evaluated using conventional angiography as the standard of reference. RESULTS: On the best arterial phase, average aortic signal-to-noise ratio (+/-SD) was 74.5 +/- 24.4, aorta-to--inferior vena cava contrast-to-noise ratio was 70.8 +/- 23.4, and inferior vena cava--to-aorta venous-to-arterial enhancement ratio was 0.03 +/- 0.04. No venous overlap was seen in 38 of 39 patients. Substantial enhancement of renal arteries was seen in all patients without any noticeable artifacts. MR angiography correctly depicted the degree of stenosis in 44 of 47 normal arteries, 13 of 16 mildly stenotic arteries, five of five moderately stenotic arteries, three of four severely stenotic arteries, and one of one occluded artery. Sensitivity and specificity for revealing greater than 50% stenosis was 100%. CONCLUSION: Time-resolved 3D MR angiography can provide high-quality arteriograms. Its performance in revealing renal artery stenosis is comparable with that of conventional angiography.


Assuntos
Gadolínio , Angiografia por Ressonância Magnética/métodos , Obstrução da Artéria Renal/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Reprodutibilidade dos Testes , Fatores de Tempo
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